This addon shows some memory information of your current target, provided the target is an NPC. This information is otherwise not available in the game.

Settings

Setting Description
ShowHexID This ID is usually used when specifying mob IDs for NM placeholders.
ShowFullID The full ID, containing zone information and mob category as well.
ShowSpeed Shows percentual deviations from regular movement speed (+x% and -x%).

Source

The latest source and information for this addon can be found on GitHub.